U.S. patent number 4,410,108 [Application Number 06/310,227] was granted by the patent office on 1983-10-18 for pressure-actuated valve for use with positive displacement filling machine.
This patent grant is currently assigned to Elmar Industries, Inc.. Invention is credited to Everett S. Minard.
United States Patent |
4,410,108 |
Minard |
October 18, 1983 |
Pressure-actuated valve for use with positive displacement filling
machine
Abstract
A pressure-actuated valve is adapted to the discharge port of a
positive displacement machine for filling, sequentially, passing
open containers with a liquid product. In response to the
sequential pulses of liquid produced at the discharge port, the
pressure-actuated valve opens and closes to deliver a predetermined
amount of liquid to a waiting container. Even with low viscosity
fluids, operation of the valve remains effective, permitting
release of fluid during the delivery period yet preventing
contaminating drips of fluid from the nozzle during non-delivery
periods. Owing to the special valve design, delivery of accurate
amounts of liquid and elimination of nozzle drip between container
filling cycles are ensured, regardless of slowdown or interruption
of machine operation. Contamination of the filling station
resulting from product splash is also eliminated despite high speed
operation of the machine.
Inventors: |
Minard; Everett S. (Sacramento,
CA) |
Assignee: |
Elmar Industries, Inc. (Santa
Clara, CA)
|
Family
ID: |
26818230 |
Appl.
No.: |
06/310,227 |
Filed: |
October 9, 1981 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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120277 |
Feb 11, 1980 |
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Current U.S.
Class: |
222/380; 141/261;
141/286; 222/494; 222/571 |
Current CPC
Class: |
B65B
39/001 (20130101); B65B 2039/008 (20130101) |
Current International
Class: |
B65B
39/00 (20060101); B67D 005/37 () |
Field of
Search: |
;222/380,494,372,491,571
;137/859,860 ;239/533.1,533.13,533.14
;141/146,392,285-310,115,116,250-284 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Bell, Jr.; Houston S.
Attorney, Agent or Firm: Lothrop & West
Claims
I claim:
1. For use with a positive-displacement receptacle-filling machine
having a base frame with an open bottom dispensing channel
extending therein along a vertical axis, a valve comprising:
a. a valve upper body adapted to be joined to said base frame and
having a passageway therethrough forming part of said dispensing
channel and extending along said axis;
b. means on the bottom of said valve upper body defining an annular
seat disposed around said passageway and concentric with said
axis;
c. a cylindrical plug including a ring having an upper ring
portion, a lower ring portion, and a central transverse plate
provided with a plurality of apertures through said plate
connecting an upper manifold chamber marginally defined by said
upper ring portion and a lower manifold chamber defined by said
lower ring portion;
d. a hub on said plate concentric with said axis, said plurality of
apertures surrounding said hub in concentric relation, the bottom
of said hub being at a predetermined elevation above the bottom
annular surface of said lower ring portion;
e. an elastomeric diaphragm of circular outline in plan and mounted
on the bottom of said hub concentric with said axis, said diaphragm
being of sufficient diameter and thickness so that in uppermost
position the peripheral portion of said diaphragm engages and is
biased downwardly by the adjacent circular corner edge of said
bottom annular surface of said lower ring portion, said diaphragm
being of a material possessing a restorative force capable of
tightly sealing said peripheral portion of said diaphragm against
said corner edge of said lower ring portion; and,
f. a nozzle fitting threadably engageable with said valve upper
body, said nozzle fitting including a bore adapted to receive said
plug and to clamp said ring against said annular seat as said
nozzle fitting is threaded on said valve upper body, said nozzle
fitting further including inverted conical side walls extending
below said ring and said diaphragm and defining a product
stream-shaped chamber having a bottom discharge port concentric
with said axis, said peripheral portion of said diaphragm being
flexed downwardly by a vertical head pressure in excess of a
predetermined amount to permit product flow from said upper
manifold chamber to said lower manifold chamber and around the rim
of said diaphragm into said product flow shaping chamber and out
said bottom discharge port.
2. A valve as in claim 1 including a screen covering said bottom
discharge port.
3. A valve as in claim 2 including a downwardly tapered nut
fastened to said hub and depending from the bottom central portion
of said diaphragm in concentric relation, the lower end of said
tapered nut touching said screen.
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
This application is a continuation-in-part of my co-pending patent
application Ser. No. 120,277 filed Feb. 11, 1980, now
abandoned.
BACKGROUND OF THE INVENTION
Most liquid products, until fairly recently, have been
machine-loaded into cans and jars using gravity, rotary, or vacuum
methods. All of these methods exhibit certain speed limitations in
the loading operation. In response to this problem, the positive
displacement filling machine was developed, and to a certain extent
has proved quite successful. The positive displacement approach
calls for a device, generally using a reciprocating piston
assembly, capable of rapid-fire injection of predetermined amounts
of the product into storage containers.
The early positive displacement machines, such as the apparatus
disclosed in my U.S. Pat. No. 3,358,719 issued Dec. 19, 1967, were
designed primarily to load liquid products of a heavier nature,
ranging from paste-like products to medium viscosity fluids
containing solid particles. While these products proved viscous
enough to permit earlier designs to operate without a special
nozzle apparatus, the low viscosity, water-thin products posed
special problems.
Contaminating product drip between load bursts and irregularities
in fill quantities plagued low viscosity fluid loading operations.
These problems were especially evident if the filling machine
slowed in operating speed or stopped entirely during loading.
Without secondary valve means to inhibit unwanted discharge flow,
the water liquid would drain from the metering pocket faster than
the displacing piston could pump it out, and overfill the
container. The low viscosity fluid also collected upon the nozzle
surface and occasionally dripped onto the upper sealing edge of the
cans, contaminating the entire contents.
The patent to Kerr, U.S. Pat. No. 3,096,914 represents an attempt
to provide a secondary valve means designed to solve the
aforementioned difficulties. The design is deficient in that it
relies on the presence of a partial vacuum above the diaphragm to
form a proper seal against leakage.
In short, the resiliency of the diaphragm itself is not sufficient
to form an effective seal during all phases of the loading cycle.
For example, if the machine were slowed or stopped during the
downward, compression stroke of the piston, the pressure above the
diaphragm would naturally exeed the atmospheric pressure. Using a
secondary valve constructed in accordance with the Kerr design, a
positive seal against dribble or leak could not exist under such
conditions.
The invention disclosed herein, while using diaphragm construction
in its valve mechanism, is designed to provide a complete seal
against undesirable leakage during all phases of the loading cycle.
Extremely resilient diaphragm construction cooperates with a unique
nozzle design, resulting in a pressure-actuated valve which
overcomes the deficiencies inherent in known prior art.
SUMMARY OF THE INVENTION
A hollow cylinder, which threads onto the discharge outlet of a
conventional positive displacement filling machine, houses a
pressure-actuated valve mechanism.
Situated within the hollow cylinder, in one form of the device, as
shown in FIGS. 1-5, is an axially centered, transverse, annular
diaphragm secured around the periphery and having a central
aperture. An axially coincident cylindrical plug includes a central
conical hub which projects downwardly into abutment with the
central portion of the resilient annular diaphragm, deforming the
annular portion downwardly, as appears in FIG. 1. A tight seal is
thereby maintained during fluid cut-off between the upper edge
portion of the annular aperture walls and the lower surface of the
impinging conical hub.
A plurality of discharge apertures extends through the body of the
plug around the conical hub, from the upper to the lower surface.
The positive displacement filling machine produces a continuous
series of pulsating discharges through the discharge outlet and
upon the upper surfaces of the plug and conical hub. The pressures
generated are such that the liquid is vigorously urged downwardly
through the plurality of discharge apertures and into the small
chamber defined by the upper surface of the diaphragm and the lower
surfaces of the plug and conical hub. In response to each
respective pulse, the annular aperture in the diaphragm deforms
farther downwardly, as shown in FIG. 2, slightly separating from
the conical hub to allow the liquid to spurt therethrough.
Following each pressure burst, the aperture immediately reforms in
tight relation about the conical hub to renew the seal.
In a modified and preferred form of device, as disclosed in FIGS.
6-9, the central portion of the diaphragm is fixed and it is the
rim or peripheral portion which flexes open or shut in dependence
upon the fluid pulses. During fluid cut-off the diaphragm rim is
tightly sealed against an adjacent circular corner edge located at
the bottom of the plug, as in FIG. 6.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a median, vertical sectional view through a filling
station of a positive displacement, reciprocating piston filling
machine with the flow control apparatus attached to the lower end
of the discharge outlet, with the diaphragm valve being of annular
configuration and shown in closed position;
FIG. 2 is a median, vertical sectional view through a filling
station as in FIG. 1, but with the annular diaphragm valve in open
position for discharging the liquid product;
FIG. 3 is a horizontal, sectional view taken along the line 3--3 of
FIG. 2, showing the plurality of discharge apertures in the upper
surface of the cylindrical plug around the central conical hub;
FIG. 4 is a vertical, sectional view of the annular diaphragm,
taken on a diameter thereof;
FIG. 5 is a top plan view of the annular diaphragm;
FIG. 6 is a vertical cross-section of a modified form of filling
station using a rim flexing diaphragm, and showing the diaphragm in
closed position;
FIG. 7 is a view similar to that of FIG. 6 but with the diaphragm
flexed open, allowing the product to pass over the outer edge of
the diaphragm, and with some of the shading removed to clarify the
disclosure;
FIG. 8 is a horizontal sectional view taken on the plane indicated
by the line 8--8 in FIG. 6; and,
FIG. 9 is an exploded sectional view of the preferred embodiment of
the valve of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The valve 11 of the invention is threadably attached to an outlet
bushing 12, or valve upper body, of a receptable filling machine
13, including a base frame. U.S. Pat. No. 3,358,719, issued Dec.
19, 1967 to E. S. Minard, to which reference may be had, teaches
the structure and operation of a similar filling machine.
As most clearly appears in FIG. 1 herein a product reservoir 14,
defined by container 15, provides a ready supply of liquid product
to be loaded. An inlet port 16 in the floor of reservoir 14
extending along a vertical axis, forms part of a dispensing channel
and communicates with a lateral passageway 17 in valve port housing
18. An upstanding cylinder 19 is positioned over the lateral
extension of the valve port housing 18 and communicates with
lateral passageway 17. A piston 21 slidably engages the inner wall
of the cylinder 19.
A valve stem assembly, generally designated 22, comprises a stem
23, an upper guide bar 24, an upper movable plug 26, a stem
extension 27, and a lower movable plug 28. Outlet bushing 12, or
valve upper body, includes an outlet port 29, also extending along
the axis and forming another part of the dispensing channel,
axially coincident with inlet port 16.
With valve stem assembly 22 in its lowermost position, as shown in
FIG. 1, the lower moveable plug 28 is slidably engaged with the
outlet port 29 and the bevel seat 31 of stem extension 27 is in
flush engagement with the inclined upper surface of outlet bushing
12.
FIG. 2 illustrates valve stem assembly 22 in its uppermost
position. Upper movable plug 26 is slidably engaged with inlet port
16 and lower movable plug 28 is entirely withdrawn from outlet port
29. The length of stem extension 27 is such that upper movable plug
26 will enter inlet port 16 just prior to the complete removal of
lower movable plug 28 from outlet port 29. Since at least one or
the other of the movable plugs is engaged with its respective port
at all times during the reciprocating vertical motion of valve stem
assembly 22, accurate alignment of the stem is maintained
throughout the cycle. Guide bar housing 32 is flange-mounted upon
casing 15 and assures proper alignment of the upper portion of the
stem.
Reciprocating motion along a vertical axis is applied to stem
roller 33 and cylinder roller 34 by cam means of conventional
design. Roller 33 and roller 34 are rotatably attached to stem bar
36 and cylinder bar 37, respectively. Bars 36 and 37 are, in turn,
laterally attached to upper guide bar 24 and piston 21, and slide
within groove 38 and channel 39, respectively. Thus, valve stem
assembly 22 and piston 21 are raised and lowered in timed
relationship by appropriate cam means.
The positive displacement filling machine 13 produces at outlet
port 29, sequential bursts of a predetermined amount of liquid
product. It will be noted that FIG. 1 illustrates the position of
the valve stem assembly 22 and piston 21 when product stored in
reservoir 14 flows through the inlet port 16 into lateral
passageway 17. FIG. 2 shows the valve stem assembly 22 in its
raised position, sealing off inlet port 16 and exposing discharge
port 29. Piston 21 (not shown in FIG. 2) is descending, driving the
product through discharge port 29. Thus, FIGS. 1 and 2 depict the
loading and discharge phases of the positive displacement filling
machine 13, respectively (also see E. S. Minard U.S. Pat. No.
3,358,719).
The valve 11 of the invention interposed between outlet bushing 12
and a container 41, or receptacle, generally comprises an
interiorly threaded discharge nut 42, or nozzle fitting, or outlet
body, including wrench flats 43 to facilitate addition to as well
as removal of the device from the filling machine. Since filling
machines are used for loading fluids of varying viscosities and the
device 11 is not necessary when loading with very high viscosity
products, quidk and easy removal of the fitting is a desirable
feature.
Axially coincident within the nozzle fitting 42 are a fixed
cylindrical plug 44, or ring, and an elastomeric diaphragm 46, or
valve annulus. As can be seen most clearly in FIGS. 2 and 3, the
fixed cylindrical plug 44 fits within a bore 47 formed in the
nozzle fitting 42. The flexible diaphragm 46, positioned
immediately beneath fixed plug 44 in a bore 45, includes an upper
marginal rim 48 (FIG. 2), having a transverse surface disposed at a
predetermined elevation, and a lower marginal rim 49. When the
device of the invention is initially assembled, the resilient
diaphragm 46 is laid within the bore 45 and the lower rim 49 mates
with an annular groove 51 in the nozzle fitting 42.
Then, the fixed cylindrical plug 44 is dropped into position, and
the upper rim 48 nests within an annular groove 52 in the fixed
plug 44. The rim and groove construction ensures that the diaphragm
46 remains axially coincident with the superposed fixed cylindrical
plug 44 and accurately flexes under the forces applied.
The core of the fixed cylindrical plug 44 comprises a centrally
positioned upper cone 53 and lower cone 54, or central cone body,
both encircled by a plurality of discharge apertures 56 leaving
cone supporting arms between them. As the device is threaded onto
the outlet bushing 12, the lower cone 54 intrudes through an
annular aperture 57 defined by a cylindrical wall in the
undistorted diaphragm 46. When the valve is fully seated,
cylindrical plug 44 snugly locks diaphragm 46 into position and
lower cone 54 downwardly depresses the upper edge or sealing corner
of the annular aperture 57, to acquire a predetermined diameter as
illustrated in FIG. 1. Owing to the considerable resiliency of
diaphragm 46, a tight seal is formed by the interface between the
upper edge of the diaphragm 46 at the annular aperture 57 and the
adjacent surface of the lower cone 54, as shown in FIG. 1.
As the filling machine 13 progresses through its load cycle,
sequential bursts of liquid product are first forced downwardly
through outlet port 29, then are radially distributed by the upper
cone 53 before travelling down through the plurality of discharge
apertures 56. The product then enters a circular chamber 58, which
interconnects all the discharge apertures 56. The circular chamber
58 introduces the liquid product against the upper surface of
diaphragm 46, urging the inner portion of the diaphragm, near the
annular aperture 57, downwardly and slightly away from the lower
cone 54. A conical wall 59 is disposed to allow adequate space for
the diaphragm 46 to flex during the fill phase of the loading
cycle. FIG. 2 clearly shows an extreme flexed position the
diaphragm 46 assumes when permitting fluid product to pass
downwardly through discharge port 61 and into the container 41.
Upon completion of the load burst, the diaphragm 46 rapidly returns
to a snug sealing relation with the lower cone 54, as shown in FIG.
1, thereby preventing product drip. Valve stem assembly 22 again
reciprocates to its lowermost position, permitting fluid product to
flow from reservoir 14 into lateral passageway 17.
Stem assembly 22 must now again be raised to seal the inlet port
16. A vertical hole 62 and a horizontal hole 63 are provided in the
movable lower plug 28 to facilitate this return trip of the stem
assembly. Vertical hole 62 and horizontal hole 63 act to equalize
the pressure between lateral passageway 17 and the void created
when the movable lower plug 28 is withdrawn.
Should the filling machine stop or slow down during a loading
period, the diaphragm 46 will act in a consistent manner. Since the
diaphragm will only permit passages of fluid if a threshold
pressure is present, a tight seal will immediately form if adequate
pressure is not supplied by the displacement piston 21. In other
words, if the piston stops its downward travel, the valve 11 will
quickly seal the inner chambers of the filling machine, preventing
overfill.
If the piston merely slows down in operation, the valve 11, will
respond by permitting fluid to emerge only in proportion to the
decreased speed and the resultant decreased pressure. Thus, it can
be seen that the valve performs in an eminently satisfactory
fashion, overcoming long standing problems associated with
mechanical filling of containers with low viscosity products.
Although the valve 11 heretofore disclosed produces a well-formed
discharge stream that cuts off sharply at the close of the filling
cycle, and is drip-free following closing, the velocity of the
product stream emerging from the centrally flexed annular diaphragm
46 is so great, when the machine is operating at the high
fill-speeds presently utilized in the industry, that some of the
product tends to splash over the rim of the container when it first
strikes the bottom.
To obviate this splash problem, reduction in fill-speed must be
made. With the present-day high costs of labor, materials and
equipment, a reduction in fill-speed becomes expensive.
In order to overcome this obstacle to achieving maximum efficiency,
the diaphragm structure and operation, as well as the housing, has
beem modified, as most clearly appears in FIGS. 6-9.
In this preferred embodiment, the low viscosity fluid product
passes around the outer rim of the diaphragm into a small chamber
directly below the diaphragm where the velocity of the product is
reduced and the stream reformed into a central flow. This stream
emerges from the housing as a relatively sluggish, easy flowing but
wide stream that eliminates all splashing, yet provides a sharp
cut-off and drip-free operation.
Operation is still further improved by providing a disc of screen
mesh across the discharge opening as will subsequently be described
in detail.
The improved valve assembly 70 of the invention is threadably
attached, as before, to the outlet bushing 12, or valve upper body,
of a positive displacement filling machine 13, and includes an
interiorly threaded discharge nut 71, or nozzle fitting, or valve
lower body, having wrench flats 72 to facilitate installation and
removal.
Axially coincident within the nozzle fitting 71 are a fixed
cylindrical plug 75 and an elastomeric diaphragm 76. As can be seen
most clearly in FIGS. 6 and 7, the fixed cylindrical plug 75
includes an outer ring 88 which fits within a bore 77 formed in the
nozzle fitting 71. The diaphragm 76, positioned immediately beneath
the plug 75 is tightly secured thereto by a screw 78 that passes
through a central hole 79 in the plug 75 and through a central hole
80 in the diaphragm 76 and into a generally conical-shaped nut 81,
or downwardly tapered nut 82 with arcuately concave side walls 82
when viewed in profile (see FIG. 9).
A centering boss 85, on the upper end of the nut 81, centers the
diaphragm 76 with the plug 75; and an annular shoulder 83, or
flange, on the nut 81 serves to hold the diaphragm tightly against
a central hub 86 of the plug 75. The central hub 86 is positioned a
predetermined distance above the lower face 87 of the outer ring 88
of the plug 75. The diaphragm 76 is of predetermined configuration
approximately as shown, so it flexes to a partially spherical shape
when tightly attached to the plug 75 as illustrated in FIG. 6. This
flexing of the diaphragm 76 creates a force within the diaphragm so
that the outer rim of the diaphragm makes a liquid-tight seal
against the adjacent corner edge 84 of the lower face 87 of the
ring 88 holding against a pressure of 3/4 lb. per inch. The upper
portion of the ring 88 encompasses an upper manifold chamber 73 and
the top of the ring 88 engages the annular seat 74 at the bottom of
the upper valve body 12.
The central hub 86 is attached to the outer ring 88 by a plate 89
which has a plurality of apertures 90 through which the liquid
product passes into a lower manifold chamber 100 marginally defined
by the lower portion of the ring 88 to engage the upper face of the
diaphragm 76.
The nozzle fitting 71 has a downwardly converging conical wall 91
located below the diaphragm and forming a chamber 93, the upper
portion of which surrounds the outer rim 92, or periphery, of the
diaphragm 76 at a predetermined distance therefrom. This chamber 93
terminates at a discharge port 94 that is concentric to the
vertical central axis 101 of the valve assembly 70 and has a
recessed bore 95 on its upper end into which a screen 96 is
positioned.
The screen 96 consists of a disc of mesh material 97 encased in a
light frame 98 to make the screen 96 a rigid member.
In FIG. 9, the upper and lower faces 99, or sides, of the diaphragm
76 tapper outward from the center making the outer thickness of the
diaphragm considerably thinner than the central part. This taper
provides a diaphragm that will have a restorative force sufficient
to close abruptly the flow of product at the end of the filling
cycle but in which only a minimum of additional force is required
to break the seal during the filling cycle.
The nut 81, as previously described, has an inverted conical shape
but with arcuately concave side walls 82. The nut 81 is located
below the flange 83 and terminates at its lower end in an apex 107
contacting the center of the screen 96, thereby holding the screen
in position at all times.
Directional arrows 108 in FIG. 7 show the flow path of the liquid
product through the invention when the diaphragm 76 is forced away
from its contact with circular corner edge 84 of the face 87.
In operation, during the short time the valve assembly 70 is in
closed position, the diaphragm's upper surface 99 in the vicinity
of the outer rim 92 is in tight sealing engagement with the
adjacent circular corner edge 84 of the plug 75, preventing the
downward movement of any residual amount of product into the
chamber 93. Concurrently, the screen 96 is effective to hold back
all the product that might be in the chamber 93 once the diaphragm
76 has closed off the flow of product from the metering chamber.
The screen 96, in other words, holds back all of the residual
product below the diaphragm and, in conjunction with the
quick-acting diaphragm, serves to eliminate any dripping which
might otherwise contaminate the filling station.
During filling, the piston head 21 almost instantaneously acts on
the relatively incompressible fluid product to build up the
pressure necessary to flex the diaphragm into the open, bell-shaped
configuration shown in FIG. 7, thereby permitting the chamber 93 to
fill quickly and form a wide, easy flowing stream which emerges
from the screen and fills the container rapidly but without any
splashing.
* * * * *